2007 A4 Quattro 2.0t


I got the rough start and idle along with EPC light. The most common recommendation I saw was to replace the crank position sensor. I replaced that and the car is worse now.....showing misfires on all cylinders, check engine and EPC light on, idle is rough and stalls but if given a small amount of gas it seems okay.

Here are the codes it registered:

p0301
p0458
p0245
p0a43
p0444
p0243
p2295
p2400


Don't know what to do next other than replacing the coils and plugs and possibly the fuel HPFP?

Advice?

 

Before you start throwing parts at it, you need to Google the codes first. P0301 is a misfire on the number one cylinder. Pull the spark plug, if it's wet (after running it a minute or two) that coil is not firing. Replace it (coil and plug) and see if the issues go away. The rest are EVAP Purge Valve issues (probably not going to cause the issues you're having). One Fuel Pressure Code (P2295) probably being tripped because of the other issues. If you had fuel pressure issues, the thing wouldn't run like said when you give it gas. The others are Turbo Waste Gate Solenoid issues. These could be a cause but that misfire on number 1 needs to be the first item addressed.

 

It actually pulled misfire codes for all four cylinders so I figured on changing the coils and plugs. But I was also concerned that I had the P2295 bc I thought that was related to the HPFP. I would think a fuel pump issue could cause misfires if the engine is not being fed right but I don't really know. It's a laypersons way of looking at that.

 

That certainly is a possibility if you're getting misfires on all cylinders. It's just not likely that all four coils would start flaking out at the same time. Fuel pressure must be adequate enough to atomize the fuel well enough coming out of the injector to burn quickly enough. If your pressure regulator has a vacuum hose to it, pull it loose and see you have fuel sitting in it or even smell fuel in the line. There should be NO fuel on that side of the diaphragm of the pressure regulator. If it does, there's your problem. Replacing the regulator might cure all the rough start/idle issues.

 

I havnt gone through all your codes to see what each one is, Category:Fault Codes - Ross-Tech Wiki will tell you exactly what each code is and possible solutions for each one. However keep in mind with combinations the possible solutions will have to be taken into account.

I read you had misfires on all cylinders, the last time I had all cylinder misfire, it was not a fuel issue rather a PCV leak more specifically the bright orange oil dipstick split on me and was allowing the engine to loose pressure.. But any number of things in the PCV system could be contributed, the PCV valve, hose, breather tube, breather valve, etc etc.